from behind. for more on this, i am joined by coral davenport,theenergyandenvironment correspondent for "national journal." you read a lot of these reports. as you read this one, what struck you as brand new? >> what's new about this report is for the past 18 years the united nation's climate change has been working towards one specific goal. that is cutting carbon emissions before the global average temperature increases by two degrees celsius or 3.6 degrees fahrenheit. that's the critical point we can't go past. it's a point of no return. what this study tells us is that the culmination of the carbon dioxide that's already in the atmosphere and the carbon dioxide that's projected to come into the atmosphere over the next few years with development from india and china is already so much that it is almost inevitable that we will go past that two-degree... that two-degree critical mark. we're pretty much on track at this point now to go past the point that we've all been trying to avoid. >> ifill: if we go past it, what happens? >> it's a big point. the two-degree mark is the point